Method for stabilizing somatotropins

Abstract

A method for preparing a dried protein product, such that the bioactivity and potential for solubility of the protein are substantially maintained when said product is administered to a living being and contacted with body fluids of said being, which comprises: (a) forming an aqueous solution comprising a mixture of said protein and an ionic detergent and (b) drying said protein-detergent mixture, wherein a sufficient amount of detergent is mixed with said protein in step (a) to substantially fully coat said protein.

We claim: 
     
       1. A method for preparing a dried natural or recombinant animal somatotropin product which comprises: (a) forming an aqueous solution comprising a mixture of a somatotropin and an ionic detergent which can bind strongly to the somatotropin, wherein the amount of the detergent is sufficient to substantially coat the somatotropin, and   (b) drying the somatotropin-detergent mixture wherein the bioactivity and potential for solubility of the somatotropin are substantially maintained when the dried somatotropin-detergent mixture is contacted with an aqueous fluid.   
     
     
       2. The method of claim 1 wherein the weight to weight ratio of detergent to somatotropin is at least about 40:60. 
     
     
       3. The method of claim 1 wherein the weight to weight ratio of detergent to somatotropin is about 1:1. 
     
     
       4. The method of claim 1 wherein the ionic detergent is an anionic detergent. 
     
     
       5. The method of claim 1 wherein said detergent comprises an alkyl sulfate. 
     
     
       6. The method of claim 5 wherein the detergent is sodium dodecyl sulfate. 
     
     
       7. The method of claim 1 wherein the ionic detergent is a cationic detergent. 
     
     
       8. The method of claim 1 wherein the somatotropin-detergent mixture is dried by lyophilization. 
     
     
       9. The method of claim 1, wherein the somatotropin is recombinant porcine somatotropin. 
     
     
       10. The method of claim 9 wherein the somatotropin is Δ7 rpST. 
     
     
       11. The method of claim 1, wherein the somatotropin is recombinant bovine somatotropin. 
     
     
       12. The method of claim 11 wherein the somatotropin is Δ4 rbST. 
     
     
       13. The method of claim 11 wherein the somatotropin is Δ9 rbST. 
     
     
       14. A dried, bioactive somatotropin-detergent product made in accordance with the method of claim 1. 
     
     
       15. The product of claim 14 wherein the weight to weight ratio of detergent to somatotropin is at least about 40:60. 
     
     
       16. The product of claim 15 wherein the weight to weight ratio of detergent to somatotropin is about 1:1. 
     
     
       17. The product of claim 14 wherein the detergent is sodium dodecyl sulfate. 
     
     
       18. The product of claim 17 wherein the somatotropin is natural or recombinant porcine somatotropin. 
     
     
       19. The product of claim 17 wherein the somatotropin is natural or recombinant bovine somatotropin. 
     
     
       20. A dried bioactive natural or recombinant animal somatotropin product which comprises a mixture of a somatotropin and an ionic detergent, wherein the detergent is bound strongly to the somatotropin and the ratio of detergent to somatotropin is such that the somatotropin is substantially fully coated by the detergent, wherein the bioactivity and potential for solubility of the somatotropin are substantially maintained when the dried somatotropin-detergent mixture is contacted with an aqueous fluid. 
     
     
       21. The somatotropin product of claim 20 wherein the weight to weight ratio of detergent to somatotropin is at least about 40:60. 
     
     
       22. The somatotropin product of claim 21 wherein the weight to weight ratio of somatotropin to detergent is about 1:1. 
     
     
       23. The somatotropin product of claim 20 wherein the detergent is sodium dodecyl sulfate. 
     
     
       24. The somatotropin product of claim 23 wherein the somatotropin is recombinant porcine somatotropin. 
     
     
       25. The somatotropin product of claim 24 wherein the somatotropin is Δ7 rpST. 
     
     
       26. The somatotropin product of claim 23 wherein the somatotropin is recombinant bovine somatotropin. 
     
     
       27. The somatotropin product of claim 26 wherein the somatotropin is Δ4 rbST. 
     
     
       28. The somatotropin product of claim 26 wherein the somatotropin is Δ9 rbST. 
     
     
       29. A process for enhancing the rate of growth of a living being which comprises administering to the living being a growth-enhancing amount of a dried bioactive somatotropin product which comprises a mixture of a natural or recombinant animal somatotropin and an ionic detergent, wherein the detergent is bound strongly to the somatotropin and the ratio of detergent to somatotropin is such that the somatotropin is substantially fully coated by the detergent, wherein the bioactivity and potential for solubility of the somatotropin are substantially maintained when dried somatotropin-detergent mixture is contacted with an aqueous fluid. 
     
     
       30. The process of claim 29 wherein the somatotropin is recombinant porcine somatotropin. 
     
     
       31. The process of claim 29 wherein the somatotropin is recombinant bovine somatotropin. 
     
     
       32. The process of claim 29 wherein the dried somatotropin product is administered by dissolving it in a biologically acceptable fluid and injecting it into the body of a living being. 
     
     
       33. The somatotropin of claim 20 wherein the ionic detergent is an anionic detergent. 
     
     
       34. The somatotropin product of claim 20 wherein the detergent comprises an alkyl sulfate. 
     
     
       35. The somatotropin product of claim 34 wherein the detergent is sodium dodecyl sulfate. 
     
     
       36. The somatotropin product of claim 20 formed by lyophilization.